Door latch



Aug. 28, 1956 H. w. FALK 2,760,804

DOOR LATCH Filed Oct. 14, 1953 INVENTOR 35' 32 M flara/d Wa/fm' Fa/A' 34gbwmam 6 9 ATTORNEY DOOR LATCH Harold Walter Falk, Minneapolis, Minnassignor to Wright Products, Inc., Dakota County, Minn., a corporationof Minnesota- Application October 14, 1953, Serial- No.- 386,035-

11 Claims. (Cl. 292164) This invention relates to an improvement in doorlatch and deals particularly with a latch. of simple construction,particularly useful on screen doors, storm doors, combination doors andthe like. p

In recent years, considerable stress has been placed upon thedesirability of reducing the labor costs of applying door latches todoors. With the present cost of labor, any saving in time which may beeffected by changing the door latch construction is extremely welcome tothe purchaser. The present invention: resides in the provision of a doorlatch which. may be easily and quickly applied to the door with aminimum of tools andusing a minimum of time.

A feature of the present invention lies inthe provision of a latchhaving a slidable latch bolt which is so devised that the entireactuating mechanism is on the outside of the door with the exception ofthe slidable bolt and its actuating lever. Thus in attaching the latchto the door, it is only necessary to bore one or two holes transverselythrough the door from side to side thereof and to bore another hole intothe edge of the door to communicate with the transverse apertures. Theentire mechanism may then be attached to the door without additionaltools,

. with the possible exception of a screw driver a'nd hammer.

A feature of the present invention resides in the provision of amechanism housing which is of relatively small size and whichaccommodates the operating mechanism, the lock, and the biasing spring.This housing may be secured to a surface of the door and issufii'ciently small so that it is not unsightly. In attaching the latchto the door, it is only necessary to extend the handle shank of thelatch through one drilled opening, to extend the slidable latch bolt andits sliding support into the aperture in the edge of the door, and toinsert the latch bolt actuating lever into a second transverse openingor into a portion of the first opening. Thus the attachment of the lockis so simple that it may be readil y applied by, anyone possessing ameans of drilling the openings and screwing the housing in place.

A feature of the present invention lies in the provision of a mechanismhousing which lies over one surface of the door and is provided with alatch bolt operating lever projecting therefrom. This lever is the onlyportion of the mechanism which is actually enclosed within the door,with the exception of the latch bolt and the handle shank. With thisarrangement the requirement for unusual. tools is obviated, the holesthrough the door being of relatively small size and Within the range ofauger bits, ordinarily found in the tool equipment of a home owner. Thenecessity for morti'cinginto the door edge or door 7 surfaces isobviated" and there is no need even for using nited States Patent 0.

r 2,760,804 Patented Aug. 28, 1956 Figure 1 is a perspective view of aportion of a door showing the latch in place thereupon.

Figure 2 is a diagrammatic view of the door before the latch is appliedthereto showing the arrangement of apertures required for attachment ofthe latch.

Figure 3 is a cross sectional view through the door latch and itsoperating mechanism showing the relationship of the parts thereof.

Figure 4 is a sectional view through the mechanism housing, the positionof the section being indicated by the line 4-4 of Figure 3.

Figure 5 is an elevation view of the mechanism housing, the position ofthe view being. indicated by the line 5-5 of Figure 3.

Figure 6 is a sectional view through a portion of the mechanism housing,the position of the view being. indicated by the line 6-6 of. Figure 4.

Figure7 is a sectional view through the latch bolt.

The manner in which the door is prepared to receive the present lock isbest illustrated in Figure 2 of the drawings. The door isindicated ingeneral by the letter A and numeral 10 designates one flat door surface.The edge of the door is designated by'the numeralll. Two holes 12 and 13are bored through the door from one surface 10 to the opposite surface,these openings preferably intersecting as illustrated to form a cavitywhich is elongated in a direction normal to the door edge 11. A hole 14is alsordrilled in the edge 11 of the door with its axis normal to thesurface of the edge and intersecting the axes of the holes 12 and 13.When these three holes have been drilled, the door is completelyprepared for the lock.

The lock is illustrated in: general by theletter B. The lock includes aknob 15 having a hub 16 detachabl'y'com nected to arectangular shank 17.The end oft-he shank 17 isequipped with a sleeve 1 9'. An elongatedhandle 20 is secured to the sleeve 19 to rotate in unison therewith.When attached the shank 17 may be oscillated ineither direction by thehandle 20 or by the knob 15. A-n escutcheon plate 21' is providedadjacent to the hub 16 of the knob 15 and isof. sufficient size toconceal the ends of the holes 12 and 13. This escutcheon plate 21 ispreferably provided with anv inturned marginal edge 22 which bearsagainst the door surface 23 opposite the surface 11.

The slidable latch bolt issupported inthe aperture 14. A thimble likemember 24 is provided with a closed end 25 and an outwardly flanged openend 26.' The closed end 25 is provided with anelongated rectangularopening 27 extending therethrough. A- pair of pointed ears 29 are struckfrom opposite sides of the sleeve 24 to extend outwardly beyond theperiphery of the sleeve and toward the flanged end thereof. These ears29 are intended to anchor the sleeve in the aperture 14 and prevent itsaccidental removal.

The latch bolt includes a plunger member formed of two parts. One partcomprises a wedge shaped member 30 which is substantially triangular incross section and circular in elevation. This 'wedge shaped member 30 isprovided with a projecting: cylindrical sleeve 31 which terminates in aninturned rim 32. The other main art of the latch bolt comprisesanelongated strip 33 having outwardly projecting shoulders 34 at one endthereof and an elongated aperture 35 near the other end thereof. Thesleeve 31 is provided with a slot 36 at its outer extremity of properdimensions to accommodate the shouldered end of the strip- 33. The endof the strip 33 extends into the slot 36 and holds the wedge shaped part30 from rotation about the axis of the sleeve 31.

p The strip 33 ,is of proper" dimensions to slidably fit through theslot or aperture: 27 in. the thimble 24. The strip is thus held fromrotation by the thimble but may be arranged with 'its inclined facedirected in either of two opposite directions. In other words, while theinclined surface is directed in one direction in Figure 3 of thedrawings, the latch bolt could be removed from the aperture 14 upondisengagement of the remainder of the mechanism and could be rotatedthrough 180 degrees and replaced so that the inclined surface would beon the opposite side.

The mechanism housing is shown in its outline form in Figure l of thedrawings. As indicated in this figure, the housing 37 is circular inoutline and is provided with a peripheral wall 39 which is directedtoward the door surface. A portion of the housing 37 is relativelythick, this part comprising a generally rectangular portion havingparallel side walls 40 which are of equal length so that the thickerportion of the housing extends through the center thereof. An outwardlyprojecting ring shaped bead 41 encircles the end of the sleeve 19 andthe housing is centrally apertured at 42. to accommodate the knob shank17.

As indicated in Figures 4 and of the drawings, the major portion of themechanism is supported upon a mounting plate 43 which is enclosed withinthe marginal peripheral walls 39 of the housing 37. The surface of theplate 43 which is normally against the door surface is shown in Figure5. The plate 43 is provided with an inwardly projecting sleeve 44centrally thereof which is designed to encircle the shank 17. The plateis also provided with an elongated slot or aperture 45 through which thelatch bolt actuating lever 46 extends. An additional elongated slot 47is provided into which a portion of the latch bolt actuating spring 49extends. This slot 47 acts to locate the spring 49 and to prevent its,movement laterally.

As seen in Figure 4 of the drawings a portion of the periphery of themounting plate 43 is bent right angularly to form a flange 50. Aslidable yoke 51 includes an apertured panel 52 which encircles theshank 17 and is provided with an aperture 53 of suflicient length topermit the plate 52 to slide. The plate 52 is provided with a flange 54along one end thereof and a spring 55 is interposed between the flanges50 and 54 to urge the slide in one direction. The plate 52 is alsoprovided with upwardly extending cars 56 which assist in holding theplatein its proper location.

A cam 57 is mounted upon the shank 17 adjacent to the slide 51. Thisbar-extends in opposite directions from the shank and is engageable withthe slide 51 to move the slide to 'its left hand position illustrated inFigure 4 of the drawings. The cam 57 normally extends parallel to theflange 54, the spring 55 expanding to push the slide toward the rightfrom the position shown in Figure 4. Obviously rotation of the shank 17in either direction from its normal position will act to engage one endof the cam against the flange 54 to move the slide 51.

As indicated in Figures 3 and 4 of the drawings, the lever 46 extendsthrough the slot 45 and through a slot 57 in the slide 51. A cooperablehousing member not illustrated in Figure 4 for the purpose of simplicityof showing, cooperates with the mounting plate 43 and is best shown inFigure 6. This cooperable mounting plate 59 is provided with a circularperiphery 60 similar to that of the mounting plate 43 and is providedwith an elongated central ofi-set portion 61 having parallel sides 62and 63. The side walls 62 and 63 extend on opposite sides of the slide51 and guide this slide in its movement. The mounting plate member 59also acts to hold the spring 55 engaged in the recess 47 of the mountingplate 43.

The cooperable mounting plate 59 is shown in Figure 3 as including anaperture 64 into which the lever 46 extends. As the mounting plate 59remains stationary, and as the aperture 64 snugly fits the end of thelever 46, this aperture acts as a fulcrum for the lever. Movement of theslide 51 acts to pivot the lever 46 from the position shown in fulllines in Figure 3 to the position shown in dotted outline in thisfigure. As the end of the lever 46 extends through the latch bolt member33, movement of the slide also acts to retract the latch bolt.

As indicated in Figure 6 of the drawings, a locking pin 65 is providedwith a reduced diameter end 66 which extends through a slot 67 in themounting plate 59 and through a registerable slot 69 in the housingmember 31. A flat spring 70 has angularly bent ends 71 and 72 whichextend into the spring aperture 47 and a spaced aperture 73 in themounting plate 43. This flat spring is upwardly bowed from the mountingplate 43 and tends to hold the pin 65 either at one end of its movementor at the other. In one position of movement, the locking pin 65 is inthe path or movement of a projection 74 on the slide 51. This projectionis shown in Figures 4 and 6 of the drawings. In the other position ofits movement the pin 65 is laterally spaced from the path of movement ofthe projection 74 and does not interfere with the movement of the slide.

The lever 46 is 'oddly shaped in order to act most effectively and toremain 'in proper position automatically. The fulcrumed end of the lever76 is bent angularly from the central portion of the lever and the leverend 77 which extends through the latch bolt is also angularly bent sothat the lever will hinge near or through right angular relation withrespect to the parts engaged. This arrangement permits the aperturesthrough which the lever extends to-fit rather snugly about the leverthus preventing excessive play which causes rattling or vibration of theparts.

The operation of the lock may now be described. The method of preparingthe door and the lock has been described. Screws or bolts may extendthrough the escutcheon plates and into the door to lock the parts of thestructure together and to hold the escutcheon plate and mechanismhousing from rotation relative to the door. Figure 1 illustrates screws79 extending into the door through the mechanism housing for thispurpose. The screws 79 also pass through the mounting plates 43 and 59.Similar screws can be employed for the escutcheon plate 21.

When the knob or handle is rotated in either direction from a formerposition, one end or the other of the cam 46 is urged againstthe flange54 of the slide 51. This causes the slide to slide across the surface ofthe mounting plate 43, compressing the spring 55. The flange 54 and thecars 56 extend into contact with the offset portion 61 of the mountingplate 59, thus holding the slide panel 52 in surface contact with themounting plate 43. Slidable movement of the slide 51 acts to exert apullingforce upon the lever 46 intermediate its ends. This action swingsthe end 77 of the lever 46 in a counterclockwise direction as viewed inFigure 3, thereby retracting the latch bolt.

I When the force is removed from the door handles the spring urges theslide 51 back into its normal position, thus swinging the lever 46 in aclockwise direction and projecting the latch bolt. This action alsorotates the cam 46 to its central starting position.

In order to lock the door, the reduced diameter end 66 of the lockingpin is moved upwardly in the slot 69 so that the body of the pin extendsin the path of movement of the projection 74 on the slide 51. Thusrotative movement of the cam forces the projection 74 against the pin 65which is held from lateral movement by engagement in the slot 67 andalso by peripheral engagement with the fixed flange 50. Thus the cam 46cannot rotate to move the slide sufliciently to retract the latch bolt.In unlocking the door the pin 66 is moved downwardly to move thepin 65out of the path of the projection 74;

In accordance with the patent statutes, I have described the principlesof construction and operation of my door latch, and while I haveendeavored to set forth the best embodiment thereof, I desire to have itunderstood that obvious changes may be made within the scope of thefollowing claims without departing from the spirit of my invention.

I claim:

1. A door latch including in combination a mechanism housing designed tooverlie the surface of a door, a shank rotatably supported by saidmechanism housing and-designed to extend through an opening in the doornormal to the surface thereof, a slide within said mechanism housing,cooperable means on said shank engageable with said slide to slide thesame upon rotation of said shank, and lever means mounted in saidhousing and projecting therefrom into an opening in said door, and latchbolt means mounted on said door externally of said mechanism housing andarranged to move on an axis parallel to said surface of the doorcooperably connected with said lever for actuation thereby.

2. The structure described in claim 1 and in which said slide isprovided with an aperture therethrough through which said lever extends.

3. A latch including in combination a mechanism housing including aslide, means supporting said slide for recoprocatory movement, arotatable shank extending through said mechanism housing and includingmeans cooperable with said slide to move the same in one direction, alever pivotally supported by said mechanism housing and having an endextending therefrom, a latch bolt positioned externally of said housingand slidably supported for movement by said extending end of said lever,and locking means extending into and out of the path of movement of saidslide and locking said slide from movement in one position thereof.

4. The structure described in claim 3 and including resilient means forurging said locking means selectively toward locked or unlockedposition.

5. A look including in combination a mechanism housing designed tooverlie a surface of a door, said housing having a number of aperturestherein, a rotatable shank extending through an aligned pair of saidapertures in said mechanism. housing normal to said surface of the door,a lever projecting through another of said apertures in said mechanismhousing and designed to extend into an opening in the door in spacedrelation to the shank, associated leverage means in said housingcooperable with said shank and said lever to pivot said lever uponrotative movement of said shank, and latch means operatively connectedto said lever externally of said mechanism housing.

6. The structure of claim 5 including with said latch means, a latchbolt slidable on a plane parallel to the surface of the door and latchengaging means on said lever cooperable with said latch bolt toaccommodate the same.

7. A door latch including in combination a mechanism housing designed tooverlie the surface of a door, a shank rotatably supported by saidmechanism housing and designed to extend through an opening in the doornormal to the surface thereof, a slide within said mechanism housing,cooperable means on said shank engageable with said slide to slide thesame upon rotation of said shank, and lever means mounted in saidhousing and projecting therefrom into an opening in said door, latchbolt means mounted on said door externally of said mechanism housing andarranged to move on an axis parallel to said surface of the doorcooperably connected with said lever for actuation thereby, and fulcrummeans at one end of said lever, said slide engaging said lever withinsaid housing mechanism intermediate said fulcrum means and said latchbolt.

8. A door latch including in combination a mechanism housing designed tooverlie the surface of a door, a shank rotatably supported by saidmechanism housing and designed to extend through an opening in the doornormal to the surface thereof, a slide within said mechanism housing,cooperable means on said shank engageable with said slide to slide thesame upon rotation of said shank, said slide including a flange againstwhich said cooperable means on said shank may engage to move said slide,lever means mounted in said housing and projecting therefrom into anopening in said door, and latch bolt means mounted on said doorexternally of said mechanism housing and arranged to move on an axisparallel to said surface of the door cooperably connected with saidlever for actuation thereby.

9. A door latch including in combination a mechanism housing designed tooverlie the surface of a door, a shank rotatably supported by saidmechanism housing and desi ned to extend through an opening in the doornormal to the surface thereof, a slide within said mechanism housing,cooperable means on said shank engageable with said slide to slide thesame upon rotation of said shank, said slide including a flange, and acooperable means on said shank and slide including a cam engageable withsaid flange to move said slide upon rotation of said shank, lever meansmounted in said housing and projecting therefrom to an opening in saiddoor, and latch bolt means mounted on said door externally of saidmechanism housing and arranged to move on an axis parallel to saidsurface of the door cooperably connected with said lever for actuationthereby.

10. A door latch including in combination a mechanism housing designedto overlie the surface of a door, a shank rotatably supported by saidmechanism housing and designed to extend through an opening in the doornormal to the surface thereof, a slide within said mechanism housing,cooperable means on said shank engageable with said slide to slide thesame upon rotation of said shank, lever means mounted in said housingand projecting therefrom into an opening in said door, said slide beingprovided with an aperture therethrough through which said lever extends,latch bolt means mounted on said door externally of said mechanismhousing and arranged to move on an axis parallel to said surface of thedoor cooperably connected with said lever for actuation thereby.

11. A door latch including in combination a mechanism housing designedto overlie the surface of a door, a shank rotatably supported by saidmechanism housing and designed to extend through an opening in the doornormal to the surface thereof, a slide within said mechanism housing,cooperable means on said shank engageable with said slide to slide thesame upon rotation of said shank, spring means for urging said slide inone direction, lever means mounted in said housing and projectingtherefrom into an opening in said door and latch bolt means mounted onsaid door externally of said mechanism housing and arranged to move onan axis parallel to said surface of the door cooperably connected withsaid lever for actuation thereby.

References Cited in the file of this patent UNITED STATES PATENTS991,018 Powers May 2, 1911 1,473,378 Moore Nov. 6, 1923 2,401,559 FalkJune 4, 1946

